Morbidity and mortality associated with the interaction of miconazole oral gel and warfarin.

Oral candidiasis is a frequently encountered oral fungal infection which can be treated with systemic and topical antifungal agents. Warfarin is a widely used oral anticoagulant. The interaction of miconazole oral gel and warfarin, causing potentiation of anticoagulant activity, has been documented over many years with evidence of occurrence in multiple settings and is a significant patient safety risk. This dangerous interaction remains underappreciated by dentists, doctors, pharmacists and patients, with resulting significant morbidity and mortality still occurring. This paper reports on recent developments concerning this interaction, and the important patient safety issues involved. In situations where topical treatment for oral candidiasis is indicated, nystatin should be prescribed instead of miconazole oral gel in patients taking warfarin, unless close monitoring and titration of the anticoagulant effect is undertaken.